How many steps does it take for humans to explore Mars? | Zhao Yuyu

There is no fire on Mars, so why is it called "Mars"?

Because it looks red and flickers, we originally called it Yinghuo (star). Mars is the name given to it by the Chinese, and Europeans called it the god of war.

In the original ancient Greek mythology, including ancient Roman mythology, it was also considered to be related to war. The English name of Mars is Mars, which is the name of the god of war in Roman mythology, and it is called Ares in Greek mythology.

▲Human speculation on Mars

Many people mistakenly believe that it has a hot temper, but it may actually be a "gentle" planet. The temperature on Mars is actually much lower than that on Earth, with a minimum temperature of minus 140 degrees Celsius and an average temperature of minus 63 degrees Celsius. It may reach a little above zero in some places, but it is very cold most of the time.

How hard are humans trying to explore Mars?

We hope that when the Mars spacecraft travels to Mars, the distance between the Earth and Mars will be the shortest, which will happen about once every 26 months. This will save fuel because it takes about eight months to fly to Mars. If we use other cycles to launch, we may need more fuel.

▲Mars exploration mission (data as of the end of 2019)

In fact, since around 1960, in the past 60 years of exploration, humans have continuously launched probes to Mars, but some probes went directly to Mars, some may have gone to Venus and then to Mars. Each probe has a different mission.

We regard 1997 as a node. Before that, there were more than 20 detections, and only about one-third were successful. But after 1997, especially in the United States, its entire detection technology became very mature, and the success rate increased greatly.

How does Tianwen-1 achieve Mars exploration?

The exploration of "Tianwen-1" can be divided into two parts, one is its orbiter and the other is the lander/Mars rover.

The Mars orbiter can conduct global exploration of Mars. Specifically, it can stay in the near-Mars orbit and fly around it, and continue to conduct remote sensing exploration of the Martian surface and space environment exploration. In this way, we can conduct many explorations of the surface composition of Mars, the magnetic field space environment, the near-surface, the structure below the surface, etc., to obtain a lot of new data.

▲China's Tianwen-1 Mars rover explores the secrets of Mars' northern hemisphere

On the other hand, there is the lander/rover. The Tianwen-1 "lander" is a landing platform to help the Zhurong rover land safely. Usually, a lander can conduct ground exploration around the landing site, but the lander itself cannot move. The rover goes a step further and can move around the surface of Mars and analyze geological targets along the way. It should be noted here that the Tianwen-1 lander does not carry any scientific payloads, and all scientific exploration depends on the Zhurong rover.

The rover is now heading to a place that has been poorly studied before - the northern hemisphere of Mars. It is difficult to see it very clearly from a remote sensing orbiter because there is a lot of dust on the surface, which makes it difficult to see from a spectroscopy perspective.

▲The blue area in the north is a lowland. China's Tianwen-1 landing site is Utopia Planitia No. 2

Our Chinese Mars rover will explore its composition, to see whether there is water ice buried underground on Mars and what the magnetic field of this place is like. Because Tianwen-1 is China's first independent mission into deep space, everything from its launch to its current on-orbit orbit correction and its landing technology are all things that China is exploring for the first time.

▲There is indeed water ice under the surface of Mars

How strong is the Tianwen-1 Mars rover internationally?

▲The landing sites of past and upcoming Mars rovers

On November 8, 2011, China's first Mars probe, Yinghuo-1, embarked on a mission to Mars with the Russian probe Phobos-Grunt. During the mission, the Phobos-Grunt probe failed to change its orbit as planned, and the mission ended in failure.

The way of Mars exploration has gradually developed with the advancement of technology. Initially, it could only be flyby exploration (also called flyby exploration). **Flyby exploration cannot enter the orbit around Mars, but only flies through the space near Mars. It can mainly obtain Mars pictures and detect atmospheric parameters, etc. **Early American probes either orbited, flew by, or placed a lander from the orbiter.

Generally speaking, each mission has a dominant detection method. For example, some missions are orbiting detection, and some missions are landing or patrol detection. However , before the Tianwen-1 mission, no mission had achieved both orbiting and ground patrol at once.

Tianwen-1 is China's first independent exploration mission of the entire Mars. This probe is very special. For the first time, it has achieved "orbiting", "landing" and "patrol" in one step. This means that the probe not only has to land, but also has to allow the rover to patrol the surface, which is very difficult. It can be said that Tianwen-1 has achieved the feat of planetary exploration.

After all, landing on Mars itself is very difficult, and the European Union has not yet succeeded once.

What other planetary exploration plans does the “Tianwen” series have in the future?

Tianwen-1 is the first in China's entire planetary exploration program , because the previous "Chang'e series" mainly conducted explorations around the moon, and now we have launched the Tianwen series.

▲The origin and evolution of planets, satellites and planetary systems

In addition to exploring Mars, the Tianwen series also has plans to explore other planets . For example, Tianwen-2 is scheduled to explore an asteroid around 2024.

Including the exploration of the Jupiter system, the spacecraft will fly for a very long time. It will fly through the asteroid belt and then reach Jupiter to conduct a relatively close exploration of the Jupiter system and one of its satellites.

In 2028, we also plan to carry out a Mars sample return mission to bring Martian samples back to Earth , so this is also something very exciting.

Can humans find the "next Earth" and migrate there?

It depends on whether we can get there quickly . For example, if we can get there as easily and quickly as taking a high-speed train or a space shuttle, it might be possible. But if a journey takes 6 to 8 months and you have to sleep there, the whole experience may not be very good.

Another question is whether we can find it . I personally think there should be planets that are very similar to our Earth.

Human exploration of the solar system is also aimed at finding some planets that may be very similar to Earth's environment or have been very similar in the past. We currently think that Mars is one of them, and in fact Venus is also very similar to Earth.

▲Scientific research has found that Mars once had liquid water, substances and energy necessary for life

These planets may have been very similar to the Earth in their early days, but they took different paths. We want to know why they took that path, and this is also something that planetary scientists are very interested in.

(This article is edited from Zhao Yu's behind-the-scenes interview video)